Interference reducing apparatus for radioreceivers



April 16, 1935. J. A. PIXLER 1,998,058

INTERFERENCE REDUCING APPARATUS FOR RADIORECEIVERS Filed Sept. 27, 1933 3 Sheets-Sheet 1 51% g 5 D 6 B 0 o a o A will J. A. PIXLER 1,998,058

INTERFERENCE REDUCING APPARATUS FOR RADIORECEIVERS April 16, 1935.

Filed Sept. 27, 1933 3 Sheets-Sheet 2 JOIUL A. lnnzntur mw v Hm wwwm.

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Aprii :16, 1935. I J-. A. PIXLER 1,998,058

INTERFERENCE REDUCING APPARATUS FOR RADIORECEIVERS Filed Sept. 27, 1953 s Sheets-Sheet s AMAAAAMAAAM'AAA'MAAF RM MA L lE/1ril1i/1llllllillllllllllr llll Q VVVVVVVVVVVVVVVVVVVVVVVVVVV VVV Patented Apr. 16, 1935 r I v UNl'lED s'rarss PATENT orrlcs INTERFERENCE REDUCING APPARATUS FOR, RADIORECEIVERS John Albert PixleigBenkelman, Nebr.

Application September 27, 1933, Serial No. 691,19?v

Claims. (Cl.'25020) This invention relates to apparatus for use rent from the coil I l and will conduct it to looped in connection with radio receivers, one of the insulated wires l3 which are twisted about each objects being to provide units of novel construcother and are supported within but out of contion for use in connection with either or both tact with the carbon tube 3.. These loops are car- 5 the aerial and the ground and which act to reried by and insulated from disks i4 supported by 5 duce interference. an insulated spindle I5. 1 i

With the foregoing and other objects in View The other end of the looped wires i3 is elecwhich will appear as the description proceeds. trically connected to the insulated coil H on a the invention consists of certain novel details of second spool, a portion of this coil being extendconstruction and combinations of parts hereined around and insulated from a coil 9 of care 10 after more fully described and pointed out in the wire adapted to receive an induced current and claims, it being understood that changes may transmit it to the core 1. The coils mounted on be made in the construction and arrangement of the two cores 6 and 1 are dup and both are parts without departing from the spirit of the illustrated by the d c o in Fi e invention as claimed. r In the unit A a magnetic force is set up be- 15 In the accompanying drawings the preferred tween the two cores 6 and. I and a portion of the form of the invention has been shown. energy received by. core 6 will be shunted through In said drawings: the carbon tube A to the core 1. As shown in Figure 1 is a diagram showing the present ap- F ur 4 Springs is can b i rp ed ween paratus connected to a radio receiver and prothe rings 5 and the cores 8 to hold the various 20 viding an artificial ground. parts properly assembled within the tube.

Figure 2 is a similar View showing the appara- Unit B which can be used with or independ tus used in connection with the usual ground. ently of u includes a be n o Carbon d Figure 3 is a similar view of a modified form the ends of the openi therein can e Closed by of ground and aerial connection. centering rings l8 carrying contact springs -|9.

25 Figure 4 is an enlarged section through the These rings serve to center terminal cores 2!) and serial and ground apparatus shown in Figure 1. 2|. Core 20 is electrically connected to one end Figure '5 is a diagrammatic view thereof. of a looped wire 22 made up of twisted strands, Figure 6 is a section through one of the inthe loops being supported by disks 23 unted duction coils.. on a central stem 24 insulated from the core 20. 30

Referring to the figures by characters of rei- The other end of the looped e is jo ed. to an erence I designates a casing preferably divided indu fiO Coil such a illustrated in l s 6, into separate compartments by partitions 2. theinner or bare wire 9 being J' e Wi Each of these compartments is designed to hold 22 while t outer or insulated W il H is 3 snugly one of the several units constituting the j ed to e 1 H of a r v ly p s t d si present invention. In thestructure illustrated in ar induction coil- The inner o h Wire l Figures 1, 2, 4 and 5 both aerial and ground units 9 Of this latter device is joined c ly t0 a are shown. The aerial units have been indicated 10013661. Wife 25 ed of twisted ds C ried at A and B while the ground units have been i by insulated disks 25 and the other end of the dicated at C, D, E, F and G, looped wireis electrically connected to the core 40 The aerial unit A comprises a tube 3 formed 2L of carbon and seated in the ends of the opening e units A and B a use in c nnection 4 in the tube are centering rings 5 form d of a with the aerial X of the radio receiver Y and can material constituting a conductor of electricity. be d either together separately If u ed A core 8 is centered in one of these rings 5 and separately, the lead 21 from the aerial X is ex electrically connected thereto while another core tended to the te minal or co e 9 While terminals I is centered in and electrically connected to the 2! and 7 a e Coupled together as at A lead other ring 5. A spool 8 of steel is mounted n 29 is then extended from the core or terminal 6 core 6 and is provided with a short coil of bare to the aerial p t 0f the v r However 0 wire, indicated at 9, this coil being covered with should it be desired to use y One Of hes units, a layer of insulation i0. Another coil ll of inas for example unit A, the aerial lead 38 would sulated wire is wrapped about the spool 8 and be extended to the terminal or core I as shown the insulation it, this large coil or" insulated wire in Figure thereby ng out unit B. being electrically connected as at l2 to the core The units 0, D, E, F and G constitute ground 6. Thus the coil 9 will receive an induced curunits. Unit C is adapted to be employed by itself 55 in connection with the usual ground, as shown in Figure 2 at which time a lead 3| would join one terminal of this unit to the ground post of the receiver while the other terminal of the unit would be joined by a connector 32 to the earth. When the connection 32 is not used the other units D, E, F and G will be employed, these being connected as illustrated in Figures 4 and 5 as well as Figure 1.

The unit C consists of a carbon tube 33 having terminals 34 and 35 mounted in centering rings 36 containing springs 31 for maintaining electrical connections between these terminals and the tube. Stems 38 are alined with but insulated from the terminals and each carries looped wires 39 which are twisted together. The two loops are electrically connected at one end as shown at 40 while their other ends are joined electrically to the respective terminals 34 and 35. These looped wires are supported in the same manner as those heretofore described, they being carried by disks The loops 38 are extended to the respective terminals 34 and 35, as shown.

The unit D consists of a coil preferably about five inches long and containing approximately seventy-two feet of insulated wire indicated at 42. The respective ends of the coiled wire are electrically connected to terminals 43 and 44.

The unit E is of the same construction as unit A, its terminals 45 and 46 corresponding with the terminals 6 and 1.

Unit F is of the same construction as unit D, its terminals 41 and 48 corresponding with the terminals 43 and 44.

Unit G is a carbon cylinder solid except for a small central bore 49 in which is mounted a rod 50 one end of which provides a terminal 5|.

The units C to G inclusive are connected in series, there being an electrical connection 52 between the terminals 35 and 43, another connection 53 between the terminals 44 and 45, a third connection 54 between the terminals 46 and 41 and another connection 55 between the terminals 48 and 5!.

When the apparatus is set up as illustrated in Figures 1, 4 and 5 the waves are received from the aerial X and enter the set by way of the units A and B. Instead of using the ordinary ground, an artificial ground is formed by the units C to G inclusive.

It has been found by actual tests that where parts are assembled as described there occurs a marked reduction in interference and a corresponding improvement in reception.

As before stated the units D to G inclusive might be dispensed with under some conditions as shown in Figure 2 and should the unit B, for example, also be dispensed with the set up would be the same as illustrated in Figure 3 wherein unit A (or, if preferred, unit B) is interposed betw e th aerial a d e input O the e W le the unit C is interposed between the ground and the ground terminal of the set.

The apparatus constituting this invention can be made complete in itself for attachment to a receiving set or, if preferred, it can be built into the set.

What is claimed is:

1. Interference reducing apparatus for radio receivers including a carbon tube having spaced terminals for electrical connections with an aerial and the input of the receiver respectively, looped wires within but out of contact with the tube, and induction coils connected to and arranged in series with the looped wires to provide an electrical connection between the terminals.

2. Interference reducing apparatus for radio receivers including a carbon tube having spaced terminals for electrical connections with an aerial and the input of the receiver respectively, looped Wires within but out of contact with the tube and induction coils connected to and arranged in series with the looped wires to provide an electrical connection between the terminals, each of said induction coils including a primary coil of bare wire and a secondary and larger coil of insulated wire.

3. Interference reducing apparatus for radio receivers including a carbon tube having spaced terminals for electrical connections with an aerial and the input of the receiver respectively, looped wires within but out of contact with the tube, and induction coils connected to and arranged in series with the looped wires to provide an electrical connection between the terminals, the ends of the tube being electrically connected to the respective terminals. v

4. Interference reducing apparatus for radio receivers including a carbon tube having spaced terminals one of which is adapted to be connected to the aerial or ground terminal of a receiver, looped wires within and spaced from the tube, and induction coils connected to and arranged in series with the looped wires to provide 'an electrical connection between the terminals, said tube also constituting an electrical connection between the terminals. 7

5. Interference reducing apparatus for radio receivers including a carbon tube having spaced terminals electrically connected thereto, looped wires connecting the terminals within the tube,

a second carbon tube having end terminals electrically connected thereto, looped wires between said terminals, induction coils connected in series with the looped wires and cooperating therewith to provide an electrical connection between the terminals, a substantially solid carbon tube having a core of conductive metal, and coiled wires interposed between the carbon tubes, said tubes and coiled wires being connected in series, thereby to provide an artificial ground.

' QHN ALBERT P R. 

